Phaser mechanisms for continuously varying the phase of a camshaft (intake and/or exhaust) relative to the crankshaft for purposes of reducing exhaust gas emissions and improving engine performance are well known in the art of internal combustion engine controls. In general, accurate knowledge of the phaser position is essential to the achievement of accurate phase angle control. However, inaccuracy can occur due to engine-to-engine variation, as well as mechanical and electrical variation within a given engine. For example, variations in engine operating temperature can produce variations in the air gap between a toothed wheel and a speed sensor, which in turn produces variations in the sensor output. Accordingly, what is needed is a method of accurately determining the phaser position in spite of such variations.